*{
    margin:0;
    padding: 0;
}

.xiezi{

    width: 100px;
    height: 100px;
    background-color: #45AB35;
}

.xiehe{
    margin-left: 100px;
    margin-top: 100px;
    width: 100px;
    height: 100px;
    padding: 10px;
    background: #4AA1EF;
    border: 5px solid red;
}


.xiezi2{

    width: 100px;
    height: 100px;
    background-color: #45AB35;
}

.xiehe2{
    margin-left: 100px;
    margin-top: 100px;
    width: 130px;
    height: 130px;
    padding: 10px;
    background: #4AA1EF;
    border: 5px solid red;
    box-sizing:border-box;
}



.center{
    margin: 50px;
    width: 300px;
    height: 300px;
    background-color: #eef;
    display: -webkit-box;
    -webkit-box-pack:center;
    -webkit-box-align:center;
    -moz-box-pack:center;
    -moz-box-align:center;
}